xref: /dragonfly/sys/sys/gmon.h (revision e98bdfd3)
1 /*-
2  * Copyright (c) 1982, 1986, 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)gmon.h	8.2 (Berkeley) 1/4/94
30  * $FreeBSD: src/sys/sys/gmon.h,v 1.15 1999/08/28 00:51:45 peter Exp $
31  */
32 
33 #ifndef _SYS_GMON_H_
34 #define _SYS_GMON_H_
35 
36 #include <machine/profile.h>
37 
38 /*
39  * Structure prepended to gmon.out profiling data file.
40  */
41 struct gmonhdr {
42 	u_long	lpc;		/* base pc address of sample buffer */
43 	u_long	hpc;		/* max pc address of sampled buffer */
44 	int	ncnt;		/* size of sample buffer (plus this header) */
45 	int	version;	/* version number */
46 	int	profrate;	/* profiling clock rate */
47 	int	spare[3];	/* reserved */
48 	/* XXX should record counter size and density */
49 };
50 #define GMONVERSION	0x00051879
51 
52 /*
53  * Type of histogram counters used in the kernel.
54  */
55 #ifdef GPROF4
56 #define	HISTCOUNTER	int64_t
57 #else
58 #define	HISTCOUNTER	unsigned short
59 #endif
60 
61 /*
62  * Fraction of text space to allocate for histogram counters.
63  * We allocate counters at the same or higher density as function
64  * addresses, so that each counter belongs to a unique function.
65  * A lower density of counters would give less resolution but a
66  * higher density would be wasted.
67  */
68 #define	HISTFRACTION	(FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
69 			 ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
70 
71 /*
72  * Fraction of text space to allocate for from hash buckets.
73  * The value of HASHFRACTION is based on the minimum number of bytes
74  * of separation between two subroutine call points in the object code.
75  * Given MIN_SUBR_SEPARATION bytes of separation the value of
76  * HASHFRACTION is calculated as:
77  *
78  *	HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
79  *
80  * For example, on the VAX, the shortest two call sequence is:
81  *
82  *	calls	$0,(r0)
83  *	calls	$0,(r0)
84  *
85  * which is separated by only three bytes, thus HASHFRACTION is
86  * calculated as:
87  *
88  *	HASHFRACTION = 3 / (2 * 2 - 1) = 1
89  *
90  * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
91  * is less than three, this algorithm will not work!
92  *
93  * In practice, however, call instructions are rarely at a minimal
94  * distance.  Hence, we will define HASHFRACTION to be 2 across all
95  * architectures.  This saves a reasonable amount of space for
96  * profiling data structures without (in practice) sacrificing
97  * any granularity.
98  */
99 /*
100  * XXX I think the above analysis completely misses the point.  I think
101  * the point is that addresses in different functions must hash to
102  * different values.  Since the hash is essentially division by
103  * sizeof(unsigned short), the correct formula is:
104  *
105  * 	HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
106  *
107  * Note that he unsigned short here has nothing to do with the one for
108  * HISTFRACTION.
109  *
110  * Hash collisions from a two call sequence don't matter.  They get
111  * handled like collisions for calls to different addresses from the
112  * same address through a function pointer.
113  */
114 #define	HASHFRACTION	(FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
115 			 ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
116 
117 /*
118  * percent of text space to allocate for tostructs with a minimum.
119  */
120 #define ARCDENSITY	2
121 #define MINARCS		50
122 
123 /*
124  * Limit on the number of arcs to so that arc numbers can be stored in
125  * `*froms' and stored and incremented without overflow in links.
126  */
127 #define MAXARCS		(((u_long)1 << (8 * sizeof(u_short))) - 2)
128 
129 struct tostruct {
130 	u_long	selfpc;
131 	long	count;
132 	u_short	link;
133 	u_short pad;
134 };
135 
136 /*
137  * a raw arc, with pointers to the calling site and
138  * the called site and a count.
139  */
140 struct rawarc {
141 	u_long	raw_frompc;
142 	u_long	raw_selfpc;
143 	long	raw_count;
144 };
145 
146 /*
147  * general rounding functions.
148  */
149 #define ROUNDDOWN(x,y)	rounddown(x,y)
150 #define ROUNDUP(x,y)	roundup(x,y)
151 
152 /*
153  * The profiling data structures are housed in this structure.
154  */
155 struct gmonparam {
156 	int		state;
157 	HISTCOUNTER	*kcount;
158 	u_long		kcountsize;
159 	u_short		*froms;
160 	u_long		fromssize;
161 	struct tostruct	*tos;
162 	u_long		tossize;
163 	long		tolimit;
164 	uintfptr_t	lowpc;
165 	uintfptr_t	highpc;
166 	u_long		textsize;
167 	u_long		hashfraction;
168 	int		profrate;	/* XXX wrong type to match gmonhdr */
169 	HISTCOUNTER	*cputime_count;
170 	int		cputime_overhead;
171 	HISTCOUNTER	*mcount_count;
172 	int		mcount_overhead;
173 	int		mcount_post_overhead;
174 	int		mcount_pre_overhead;
175 	HISTCOUNTER	*mexitcount_count;
176 	int		mexitcount_overhead;
177 	int		mexitcount_post_overhead;
178 	int		mexitcount_pre_overhead;
179 };
180 extern struct gmonparam _gmonparam;
181 
182 /*
183  * Possible states of profiling.
184  */
185 #define	GMON_PROF_ON	0
186 #define	GMON_PROF_BUSY	1
187 #define	GMON_PROF_ERROR	2
188 #define	GMON_PROF_OFF	3
189 #define	GMON_PROF_HIRES	4
190 
191 /*
192  * Sysctl definitions for extracting profiling information from the kernel.
193  */
194 #define	GPROF_STATE	0	/* int: profiling enabling variable */
195 #define	GPROF_COUNT	1	/* struct: profile tick count buffer */
196 #define	GPROF_FROMS	2	/* struct: from location hash bucket */
197 #define	GPROF_TOS	3	/* struct: destination/count structure */
198 #define	GPROF_GMONPARAM	4	/* struct: profiling parameters (see above) */
199 
200 #ifndef _KERNEL
201 
202 #include <sys/cdefs.h>
203 
204 __BEGIN_DECLS
205 void	moncontrol(int);
206 void	monstartup(u_long, u_long);
207 __END_DECLS
208 
209 #endif /* !_KERNEL */
210 
211 #endif /* !_SYS_GMON_H_ */
212